Huo Yunlong, Kassab Ghassan S
Department of Biomedical Engineering, University of California, Irvine, USA.
Am J Physiol Heart Circ Physiol. 2006 Sep;291(3):H1074-87. doi: 10.1152/ajpheart.00200.2006. Epub 2006 Apr 14.
The pulsatility of coronary circulation can be accurately simulated on the basis of the measured branching pattern, vascular geometry, and material properties of the coronary vasculature. A Womersley-type mathematical model is developed to analyze pulsatile blood flow in diastole in the absence of vessel tone in the entire coronary arterial tree on the basis of previously measured morphometric data. The model incorporates a constitutive equation of pressure and cross-section area relation based on our previous experimental data. The formulation enables the prediction of the impedance, the pressure distribution, and the pulsatile flow distribution throughout the entire coronary arterial tree. The model is validated by experimental measurements in six diastolic arrested, vasodilated porcine hearts. The agreement between theory and experiment is excellent. Furthermore, the present pulse wave results at low frequency agree very well with previously published steady-state model. Finally, the phase angle of flow is seen to decrease along the trunk of the major coronary artery and primary branches toward the capillary vessels. This study represents the first, most extensive validated analysis of Womersley-type pulse wave transmission in the entire coronary arterial tree down to the first segment of capillaries. The present model will serve to quantitatively test various hypotheses in the coronary circulation under pulsatile flow conditions.
基于冠状动脉血管系统的测量分支模式、血管几何形状和材料特性，可以准确模拟冠状动脉循环的搏动性。在先前测量的形态计量学数据基础上，开发了一种Womersley型数学模型，用于分析整个冠状动脉树在舒张期无血管张力情况下的搏动性血流。该模型基于我们先前的实验数据纳入了压力与横截面积关系的本构方程。该公式能够预测整个冠状动脉树的阻抗、压力分布和搏动性血流分布。通过对六个舒张期停搏、血管扩张的猪心脏进行实验测量对该模型进行了验证。理论与实验结果吻合良好。此外，目前低频下的脉搏波结果与先前发表的稳态模型非常吻合。最后，可以看到血流的相位角沿着主要冠状动脉主干和初级分支向毛细血管方向减小。本研究代表了对整个冠状动脉树直至毛细血管第一段的Womersley型脉搏波传播进行的首次、最全面的验证分析。当前模型将用于在搏动性血流条件下对冠状动脉循环中的各种假设进行定量测试。
